Coach Brian Ashton expressed his disappointment with Saturday's ragged display by world champions England but insisted it would have no bearing on next Friday's key clash with South Africa.

England struggled to a 28-10 victory over a committed United States side in the opening game of Pool A but the coach refused to read anything deep and meaningful into the below-par display.

"We were disappointed with the performance," Ashton said after tries by Jason Robinson, Olly Barkley and Tom Rees secured the win but did nothing to quieten the doubters.

"(We need more) physicality in the tackle, we need to be a lot cleaner and more efficient than we were this evening," he said.

"But next Friday will be something totally different against a side that play a completely different way.

"We've got the most massive game since I took over as England coach looming. Mentally there is a bit of work to do but playing against the green and gold of the Springboks sharpens the senses.

"We've already done our analysis of South Africa we know how to play them, now it's a question of sitting down and thinking through selection to make sure we get the right players on the field to play the way we want to."

Captain Phil Vickery was more forthright when looking ahead to the Stade de France clash.

"We've certainly got to play a lot better than this evening that's for sure," he said.

"They made it difficult for us but that performance was unacceptable by the standards we have set ourselves."

Vickery will have a nervous couple of days as he awaits a possible citing for a first-half trip on US centre Paul Emerick that went unseen by the referee.

"It was just instinctive to try to stop him, unfortunately I tapped him, luckily he got up," said the prop.

"There was certainly no malice on my part."

For Vickery to face a hearing the citing officer would have to decide, within 48 hours, that the offence would have merited a red card.

United States coach Peter Thorburn welcomed his team's performance as a "moral victory".

"We certainly achieved the private goals we gave ourselves," said the New Zealander.

Captain Mike Hercus added: "I was very proud of the guys. After a while when we realised we could hold it to them I was actually a bit disappointed we didn't take some of our opportunities."

His team did cross the line in the final minutes when replacement prop Matekitonga Moeakiola became the toast of his splendidly-named amateur club in Utah, Park City Haggis.

"The fact that we got those opportunities against the world champions is good for us," Hercus added.

"But it was one of those games - as much as England tried to get up for it was a grand final for us, it's not for them."

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